Ferrous base alloy

ABSTRACT

A HIGH-CARBON FERROUS BASE ALLOY IS DESCRIBED, CONTAINING CHROMIUM AND NICKEL, AND RELATIVELY LARGE AMOUNTS OF VANADIUM, THE ALLOY, DUE TO ITS VANADIUM CONTENT, HAVING A HIGH IMPACT RESISTANCE, AND EXCELLENT WEAR OR EROSION RESISTANCE. THE ALLOY IS PARTICULARLY USEFUL FOR MAKING CASTINGS, SUCH AS SAND SLINGER BUCKETS, AND THE LIKE.

United States Patent ()ifice 3,669,653 Patented June 13, 1972 ABSTRACT OF THE DISCLOSURE A high-carbon ferrous base alloy is described, containing chromium and nickel, and relatively large amounts of vanadium, the alloy, due to 'its vanadium content, having a high impact resistance, and excellent wear or erosion resistance. The alloy is particularly useful for making castings, such as sand slinger buckets, and the like.

In my US. Pat. No. 2,189,131, there is disclosed a ferrous base alloy consisting essentially of from 3.5 to carbon, 4 to 30% chromium, .25 to nickel, and the remainder iron.

In my U.S. Pat. No. 2,208,116, there is disclosed a ferrous base alloy consisting essentially of from 3 to 5% carbon, 8 to 30% chromium, 1 to 10% silicon, and the remainder iron.

In both patents, it is stated that vanadium may be added to the alloy in quantities of from about .20 to about 1%, for the purpose of imparting to the alloy increased toughness, and in the welding rod, a degree of stickability which is advantageous, this term defining the property or ability of the weld metal, deposited by the welding rod, to resist separation from the base metal, under severe impact.

In Pat. 2,189,131, titanium may be added to the alloy, as an optional ingredient, in amounts of .10 to 1%, and molybdenum may be added to the alloy as an optional ingredient, in amounts of '6 to 10%.

An alloy, which has been sold by Coast Metals, Inc.,'

under the foregoing patents, known as Coast Metal high nickel No. 1 alloy, consists of 3.75% carbon, 16% chromium, 8% nickel, .5 vanadium, and the balance iron.

This alloy has been sold for use in making or casting sand slinger buckets, which are used to fling foundry sand into a sand mold, for the purpose of filling the mold. The sand slinger buckets are thus subjected to a great amount of Wear or erosion by the sand, and the buckets made of the alloy have been found to have a life of the order of four to eight times that of buckets made of conventional cast materials.

However, there has always been a question of breakage of the buckets due to the fact that the buckets are held or clamped tightly in a frame, and also due to the presence of tramp iron.

I have found, as the result of extensive tests, that by increasing the amount of vanadium in such alloys to a range of from about 2.5 to about 5.0%, the impact resistance of the alloy is increased at least 50%, and with out any decrease in the wear resistance of the alloy, there being, in fact, a slight increase in the wear resistance. Vanadium, in amounts below this range, do not produce such an effect, and while vanadium in amounts slightly above this range can be used, the cost of the alloy is substantially increased by the use of such an excess.

Best results, from the viewpoint of both impact and wear resistance, particularly for use in castings such as sand slinger buckets, where both high impact and wear or erosion resistance are important factors, are obtained by using alloys within the following range:

Range, Preferred,

percent percent Vanadium 2. 5 5. 0 3. 5 Silicon 1 1. 50 .5 Iron Balance Balance 1 Maximum.

The alloy is an austenitic type alloy, and has a microscopic structure which differs substantially from that of the vanadium-free or low vanadium alloy, to which reference has been made. The difference in impact resistance between the two is indicated by that fact that a thin fragment of the vanadium-free or low-vanadium (less than 1%) alloy breaks quite easily when struck at a certain force, whereas a fragment of the same dimensions of the high-vanadium alloy requires several blows of the same force to break it.

Although the invention has been described more particularly with reference to its use in making sand slinger buckets, it may be used for many other applications or uses, where high impact resistance, as well as wear or erosion resistance caused by material sliding over the surface of the article are necessary. The alloy may also be used in the form of weld rods.

Having thus described my invention, I claim:

1. A ferrous base alloy consisting of 3.00 to 4.50% carbon, 13 to 20% chromium, 7 to 12% nickel, 2.5 to 5.0% vanadium, and the balance essentially all iron.

2. A ferrous base alloy consisting of about 3.75% carbon, about 16% chromium, about 8.5% nickel, about 3.5% vanadium, and the balance essentially all iron.

3. The method of increasing the impact resistance of an alloy consisting of carbon, chromium, nickel, and the balance essentially all iron, which consists in adding vanadium to said alloy in amounts such that the final alloy will consist of 3.00% to 4.50% carbon, 13 to 20% chromium, 7 to 12% nickel, 2.5 to 5.0% vanadium, and the balance essentially all iron.

4. A sand slinger bucket made of a ferrous base alloy consisting of 3.00 to 4.50% carbon, 13 to 20% chromium, 7 to 12% nickel, 2.5 to 5.0% vanadium, and the balance essentially all iron.

5. A sand slinger bucket made of a ferrous base alloy consisting of about 3.75% carbon, about 16% chromium, about 8.5% nickel, about 3.5% vanadium, and the balance essentially all iron.

References Cited UNITED STATES PATENTS 1,876,411 9/1932 Gregg 75-12 8 V X 2,208,116 7/1940 Cape 75-128 D 3,086,858 4/1963 IEdminster 75-128 1,963,525 6/1934 Gregg 75-128 V X L. DEWAYNE RUTL-EDGE, Primary Examine" J. 'E. LEGRU, Assistant Examiner US. Cl. X.R. 

